Fluid-operated drill.



o. H. PECK. FLUID OPERATED DRILL.

APPLiCATlON FILED JUNE 14, 1912.

' Patented Feb. 22, 1916.

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Patented Feb. 22, 1916.

C. H. PECK.

FLUID DPERATED DRILL.

APPLICATION FILED IuNE I4. I9I2.

TED sfrAs Frio.

CAID H. PECK, F ATHENS, PENNSYLVANIA, ASSIGNOR T INGERSOLLRAND COMPANY,

0F NEW YORK, N. Y., A CORPORATION 0F NEW JERSEY.

FLUID-OPERATED DRILL.

Specification of Letters Patent.

Application led June 14, 1912. 'Serial No. 703,763.

To all whom z't may Concern:

Be it known that I, CAID H. PECK, a citizen of the United States, residing at Athens, in the county of Bradford and State of Pennsylvania, have invented certain new and useful Improvements in Fluid-Operated Drills. of which the following is a specification.

This invention relates to fluid operated drills and more particularly to that class of drills which are adapted for use in drilling holes in close proximity to a wall or other object, or in corners, or in other positions where the space is restricted in one or more directions.

The drills heretofore used for this purpose have ordinarily comprised a drill spindle driven by ratchet arms or levers which have always been actuated by more or less complicated systems of cranks and gears from pistons reciprocating in longitudinally placed cylinders by fluid pressure.

The object of the present invention is to provide a drill of this character in which the ratchet arms or levers are directly secure to the connecting rod of the piston, producing a tool of great simplicity on account of its few parts, and of unusual lightness. which can be easily and cheaply constructed and yet be of high efficiency and economy.

With this and other objects in view which will appear furtherin the specification and claims l have devised a drill a practical embodiment of which is shown in the accompanying drawings in which- Figure 1 is a vertical longitudinal section partly in elevation of the complete drill taken on'the line 1-1 of Fig. 2. Fig. 2 is a horizontal longitudinal section of the cornplete drill taken on the line 2-2of Fig. l. Fig. 3 is a longitudinal section through the valve taken in the line 3-3 of Fig. 2. Figs. 4, 5 and 6 are transverse sections through the valve and connections taken respectively on the lines 4 4, 5-5 and 6--6 of Fig. 3. Fig. 7 is a section of the throttle on the line 7-7 of Fig. 2 and Fig. 8 is a det-ail showing the spring plate employed for securing the piston connecting rods in position.

The drill as shown comprises a casing 1 into which is fitted the casting containing the cylinders 2 and 3 and the valve 4. This casting is provided with a 4flange 5 which is secured by bolts 6 to the casing. In this casting are the two cylinders 2 and 3, placed side by side and at right angles to the length of the casing. In the cylinders 2 and 8 re- .ciprocate pistons 7 and 8. These pistons are provided on the inside with cups 9 and 10 and spring cover plates 11 and 12 which form sockets for receiving the ball ends 13 and 14 of connecting'rods 15 and 16. The other ends of the connecting rods are fastened by pins 17 and 18 in yokes 19 and 20 on the ends of the spindle operating ratchet arms 21 and 22; which rotate the drill spindle. The drill spindle 23 passes through cylindrical apertures in the extremities of the ratchet arms forming a fulcrum and bearing for them and is provided with longitudinal teeth 24 which are engaged by spring pressed pawls 25 and 26 set in the ratchet arms. The lower part 27'v of the spindle is free from teeth and bears in a bushing 28 in the spindle sleeve 29 which is an integral part of the main casing 1. The upper part 30 of the spindle is for a short distance also free from teeth and bears in a bushingl in the spindle sleeve, 29. The upper end of the spindle bears against a thrust bearing composed of two washers 32 and 33 between which is placed a ball ring 34. This is held in position by a nut 35 threaded into the upper end of the spindle sleeve. Threaded into the nut is a telescope feeding screw comprising an internally and externally threaded sleeve 36 inside of which is a smaller threaded rod 37 provided at its upper end with the usual squared off projecting portion 38 for the application of a rotating ratchet. The lower ends of both parts of the feeding Screw extend for some distance into a socket in the-top of the drill spindle in order to get greater feeding length. The lower end of the feeding screw is provided with a 'cylindrical boss 39 which is adapted to proiect in to the drill chuck 40 and eject the drill when the feed screw approaches its lowest position.

On the inner sides of each of the ratchet arms near their middle points are arcuate racks 41 and 42 which engage opposite sides of a beveled pinion 43 which is secured between the cylinder casting and an arm 44 projecting therefrom, by a bolt 44a upo-n which it rotates. This rack 'and pinion construction positively determ-ines the relative position of the ratchet arms and has a further function which will appear later.

The reciprocation of the pistons is controlled by the spool valve -1 which reciprocates in a bushing 45 set into a. valve bore in the cylinder casting outside of the casing. The bushing and valve are retained in the bore by screw plugs 46 and 47 which are threaded into the ends of the bore and form the ends of the-valve cylinder. The valve spool is entirely symmetrical and is provided with a central annular groove 48 controlling the inlet to both cylinders and two outer annular grooves 49 and 50 controlling.,r the exhausts from the cylinders. Operating fluid is admitted to the central annular groove b v an annular port 51 communicating with the handle. On each side of this annular port are annular ports 52 and 53 so placed that the central annular groove of the valve will connect one or the other with the fluid admission port in either of its positions. From these ports, passages 54 and 55 lead respectively to the bottom of the cylinders 2 and 3. On the outer sides of the annular ports 52 and 53 are exhaust ports 56 and 57 connecting with passages 58 communicating in each direction' with the atmosphere. These exhaust ports 56 and 57 are so placed that they will be alternately connected by the outer annular grooves -19 and 50 in the valve with the annular ports 52 and 53 which are in communication with the bottoms of the cylinders. From clearance spaces 59 and 60 in the 4ends of the'valve cylinder, which are formed by bosses'Gl and 62 on the .inne-r faces of the screw plugs 46 and 17 forming the cvlindcr heads valve o )eratinn' assa es 63 and 61 lead to their respective cylinders 2 and 3 opening therein at points which on account ot' the length and stroke of the pistons are just cleared by the opposite edges of the two pist-ons at` the extremity of their strokes, so that each end of the valve cylinder will be alternately opened to atmosphere and exposed to the pressure on the inside of the adjoining cylinder and be reciprocated accordingly. To prevent the valve from fluttering by keeping aconstant small pressure on it. when thrown,small leak ports` 65 and 6G are provided which extend from each of the annular ports 52 and 53, to the end of the cylinder farthest from it. The pressure in these will tend to hold the valve in whichever position it happens to be until it is positively thrown.

Into a socket. 67 on the rea-r side of the cylinder casting is threaded a handle 68 which forms a duct for the admitted air. In the part of the handle nearest the tool a device for automatically governing the air admission according to the load is provided which is constructed as follows: In the extreme end of the handle is an inlet plug 69 into which the operating Huid can enter by two paths, either through a contracted beveled nozzle 70 on the end of the plug or through lan annular chamber 71 and free openings 72 in the side of the plug. Coacting with this plug is a. differential area piston comprising a head 73 and a shank 74 of smaller diameter which is provided with a hollow bore 75. The end of this bore is beveled to seat against the beveled end of the plug nozzle 70. Back of the piston is a spring 76 tending to press the piston against the plug nozzle 70. The space 77 back of the piston head is connected to atmosphere by ports 78. The rest of the handle comprises a throttle of usual construction consisting of a rotatable sleeve 7 9 provided with elongated ports 80 and 81, which bridge or do not bridge the cross ports 82 through a small angle through the medium of the ratchet 25. At the same time the rack 41 on the lever will rotate the pinion 43 which will necessarily communicate an opposite. motion to the rack 42 on the other lever 22, moving it and the attached piston 3 downwardly. With the valve in the position shown, the fluid under the piston will exhaust freelyl through the cylinder passage .55, annular port 53, annular exhaust port 57.

and exhaust passage 58 to the atmosphere. When the piston 2 reaches the top of its stroke its lnner edge will just clear valve operating passage 63, allowing live fluid to' exert pressure on-the valve tending to throw it, at the same time the outer edge of the other piston will open the valve operating passage 64 from the other end of the valve cylinder to the atmospheric pressure of the casing allowing the valve to be quickly and positively thrown, which will cause a similar cycle of operation but with the Huid operating inthe other cylinder. The automatic governor operates in the following manner: If the load is light the governing piston takes the position shown in the figures, so that only as much air can enter the tool as can pass through the constricted plug nozzle 70. If the tool is now put against the work and its motion retarded the air admitted cannot all pass through the cylinders and consequently a back pressure is accumulated whlch 'forces back the piston and allows luid to enter freely through the full opening of the piston bore. If this governor were not provided the tool would race under rdirect connection of the pistons with the ratchet arms or levers, not only gets rid of the extra weight ofv the cranks and gears heretofore used but also greatly reduces the amount of power lost in transmitting the reciprocation of the pistons to the rotation of the drill. The rack and pinion connection between the levers keeps the pistons in exact relative position and also obviates the necessity of providing cylinders which can reciprccate their pistons in both directions by fluid pressure, thus enabling one end of the cylinders to be open. In the present case fluid is admitted to only oneside of the piston, the other piston producing the reverse movement of the first through the rack and pinion mechanism. This not only cheapens and simplifies the cylinder construction but also the'valve and its connections. A-further advantage of the present construction is that the valve and cylinders are all in one piece which slides into the casing, so that if it is desired to take the tool apart for examination or repair, the drill spindle can -be removed, and the entire remainder of the operative parts of the tool can be removed from the casing as a whole without being disassembled.

It is to be understood that then present showing and description discloses only one specified modification of my invention and other forms and modifications are included inthe spirit and scope of the invention as expressed in the claims.

What I claim is:

1. In a fluid operated drill, an elongated casing, a drill spindle in one end of said casing, ratchet levers for rotating said spindle extending longitudinally of said casing, cylinders in said casing at right angles to its length, oppositely reciprocable pistons in said cylinders, and connecting rods connecting said pistons and levers.

2. In a iiuid operated drill an elongated casing, a drill spindle journaled in one end of said casing, ratchet levers engaging said spindle, said levers extending longitudinally of said casing, cylinders in said'casing at right angles to its length, oppositely reciprocable pistons in said cylinders, and connecting rods connecting said pistons and said levers.

3. In a fluid operated drill, an elongated casing, a drill spindle in one end of the casing, a plurality of ratchet levers for actuating said spindle extending longitudinally of said casing, a plurality of cylinders in said casing at right angles to its length, pistons in said cylinders, connections for transmitting the motion of said pistons directly to said levers and means for successively actuating said pistons.

4. In a Huid operated drill, an elongated casing, a drill spindle in one end of the casing, a plurality of ratchet levers in said casing arranged to'successively actuate said spindle, a plurality of cylinders in said casing arranged :it rlght angles to said levers, and pistons in said cylinders directly connected with said levers.

CAID H..PECK.

Witnesses:

W. H. HAVERLY, M. S. BUn-KLEY. 

